Table 3.
Clinical improvement on depressive symptoms and insomnia severity
| Baseline | Post-test | 6 months follow-up | ||||
|---|---|---|---|---|---|---|
| i-Sleep (n = 52) | Sleep diary (n = 52) | i-Sleep (n = 45) | Sleep diary (n = 47) | Chi-square test of conditions (χ2) | i-Sleep (n = 39) | |
| PHQ-9 > 10a | 27 (52%) | 21 (40%) | 4 (9%) | 13 (28%) | χ2 (1) = 5.38, p = 0.02 | 4 (10%) |
| PHQ-9 < 5b | 0 | 0 | 28 (62%) | 11 (23%) | χ2 (1) = 14.19, p < 0.001 | 22 (56%) |
| Clinically meaningful change PHQ-9c | 29 (64%) | 14 (30%) | χ2 (1) = 11.09, p < 0.001 | 29 (51%) | ||
| ISI > 10d | 52 (100%) | 52 (100%) | 17 (38%) | 43 (85%) | χ2 (1) = 29.24, p < 0.001 | 19 (50%) |
| Clinically meaningful change ISIe | 29 (64%) | 4 (9%) | χ2 (1) = 31.27, p < 0.001 | 29 (56%) | ||
a
Recommended cut-off point when using the PHQ-9 as a screener for depression (Kroenke and Spitzer, 2002).
b
At least mild depressive symptoms, see inclusion criteria (Spitzer et al., 1999).
c
PHQ-9 drop of 50% or more resulting in a score below 10 (Spitzer et al., 1999).
Note: at baseline, all participants had a PHQ-9 score of ⩾5 due to inclusion criteria.
d
A clinical cut-off of 10 on the ISI is often used in insomnia research (Morin et al., 2011).
e
A change of 8 points or more; considered to be a clinically meaningful change (Morin et al., 2011).
Note: At baseline, all participants had an ISI score of >10 due to the inclusion criteria.